Not Applicable
Not Applicable
Not Applicable
1. Field of the Invention
This invention relates to the field of measurement and marking. More specifically, the invention comprises an improved framing square incorporating fixed pins and slidable carriages which allow the user to more easily mark desired angles on objects to be cut.
2. Description of the Related Art
Carpentry framing squares have been in common use for over a century. Most squares are composed of two legs forming a right angle. The longer leg is generally referred to as the xe2x80x9cbodyxe2x80x9d, with the shorter leg being referred to as the xe2x80x9cblade.xe2x80x9d Both the body and blade are typically marked with scales along their edges. These scales allow the user to mark desired cutting angles on lumber. However, the use of the scales is somewhat cumbersome since the user must visually align the marks on the scale with the edge of the lumber.
The limitations inherent in the visual alignment approach have been recognized for many years. U.S. Pat. No. 503,050 to Lantz (1893) discloses a solution to this problem which is now in common use. The Lantz invention employs two sliding stops which are clamped to the edges of the framing square. These stops incorporate fixed reference points which are butted against the edge of the board to be cut.
Carpenters must often make many repetitive cuts. If, for example, roofing rafters are being cut to length, then the carpenter might make fifty xe2x80x9c3 in 12xe2x80x9d cuts in a row. The Lantz device is effective in this scenario. Once the carpenter has set the sliding stops in the correct position, the square may be butted against each successive board and the correct cutting angle will result. Unfortunately, however, the clamps disclosed in Lantz must be removed prior to using the square for other purposes. They are then often lost or damaged. Thus, the prior art devices for automating the marking of cutting angles using a framing square contain inherent limitations.
The present invention comprises an improved framing square having integral features for automating the marking and cutting of angles. The square contains two sliding carriagesxe2x80x94one in the body and one in the blade. Each carriage has a deployable pin. In order to set an angle, the user first deploys the pins in each sliding carriage so that they protrude downward from the square. Next, the user sets the sliding carriage in the body to the desired position and locks it in place. The user then sets the sliding carriage in the blade to the desired position and locks it in place. The two pins protruding from the sliding carriages are then butted against the board to be cut. Once they are in place, the blade of the square will form the correct cutting angle across the board.
Since many common cuts employ a twelve inch base leg, the invention includes another feature: Rather than set the sliding carriage within the body to twelve inches, the user may opt instead to deploy a fixed pin located in the body at the twelve inch position. The user then only needs to adjust the sliding carriage within the blade to create a xe2x80x9c3 in 12xe2x80x9d, xe2x80x9c5 in 12xe2x80x9d, xe2x80x9c7 in 12xe2x80x9d, or other desired angle. A second fixed pin is provided at the seventeen inch position on the body. This pin corresponds to the base length commonly used for making hip rafters.